Go语言视频零基础入门到精通

aopre8

Java学習者論坛
我自己写了一个
import javax.Servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
;
public class URLServlet extends HttpServlet {
  public  void forwardUrl(HttpServletRequest request, HttpServletResponse response , String url)
                  throws ServletException, IOException {
   RequestDispatcher rd = getServletConfig().getServletContext().getRequestDispatcher(url);
    try{
             rd.forward(request,response);
    }catch(IOException e) {
       throw new IOException("页面跳转出项异常");
    }
  }
}
不知道为什么在其他Servlet中调用的时候，总是出錯。而把它放到同一个Servlet中就可以运行没有问题，不知道怎么回事。或者改成 response.sendRedirect也没有問题，就是用forward的时候出现问题
我想知道大家是怎么做页面跳轉类的。可以给一个给小弟用么？
出错信息是：
java.lang.NullPointerException
at net.javasp.www.servlet.LoginServlet.doPost(LoginServlet.java:79)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:243)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:190)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.valves.CertificatesValve.invoke(CertificatesValve.java:246)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2347)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:170)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:170)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.connector.http.HttpProcessor.process(HttpProcessor.java:1027)
at org.apache.catalina.connector.http.HttpProcessor.run(HttpProcessor.java:1125)
at java.lang.Thread.run(Thread.java:536)


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mone12

the jump has two types:
example: http://localhost:8080/yourwebapp/youraction.do
1, you can jump to youraction.do from yourwebapp
    the path is related
2. you can jump to youraction.do from http://localhost:8080/
    the path redirect
if you make clear about those, your question will be solved

可可西西

getServletContext().getRequestDispatcher("/*.jsp").forward(request,response);